Thread cutter for sewing machines



E. H. A. HABBERT AND E. STONE.

THREAD CUTTER FOR SEWING MACHINES.

APPLICATION man FEB. a. 1919.

1,41 1 ,089, Patented Mar. 28,1922.

INVENTORS @524? M A T RNEY' UNITED STATES PATENT OFFICE.

ENNO H. A. HABIBERT AND ELMER sroNE, or 'rRoY, NEW YORK, ASSIGNORS TO THE SINGER MANUFACTURING-COMPANY, A conronA'rIoN or NEW JERSEY.

THREAD CUTTER FOR SEWING- MACHINES.

Specification of Letters Patent. Patented lvlar, 28, 1922;

Application filed February a, 1919. Serial 1%. 275,712.

To all whom it may concern: 7

Be it known that we, ENNO H. A. HAB- Bnn'r and ELMER STONE, citizens of the United States, residing at Troy, in the county of Rensselaer and State of New York, have invented certain new and useful Improvements in Thread Cutters for Sewing Machines, of which the following is a specification, reference being had therein to the accompanying drawings. I

This invention relates to sewing machines and especially to thread-cutters for use therewith. 1 x

In the manufacture of wearing apparel it is frequently desirable to stitch uite a number of articles in succession without stopping the operationof the machine, the successive articles being connected by a chain of stitching which it is necessary to sever subsequently. This has been done/heretofore with the ordinary scissors and ithas also beendone witlra variety of cutting attachments which are more or less awkward to manipulate and obstructive.

The present invention aims to provide a simple inexpensive and eflicient cutting mechanism for severing chains of stitches connecting successive articles shortly after they pass from under the presser-foot, a

cutting mechanism which may be used with facility and without hampering the operator in introducingsuccessive pieces of work into the machine.

;It. further aims to simplify the construction of such cutting mechanisms by utilizing an already existing feature of construction on a commercial form of machine.

s The constructioncomprises a pair of cutting blades one mounted on-a cloth-plate of .the machine in rear of the presser-foot and the other mounted on the rear end of a. V presser-foot lifting lever which normally has its front end separated slightly from a lug on thefprcsser-foot. The presser-ioot lifti'ng lever has] a limit-ed movement independently of the presser foot and thislimited movement-is utilized to permitv a cutting stroke of the blade mounted thereon without lifting the resser-foot from its cooperative relation with the feed-dog. In this way chains of stitches between successive articles 1 may be out without stopping the operation of the machine.

The invention is illustrated in the accompanying drawings in which Fig. 1' is an end elevation of an overseaming machine to which the invention has been applied. Fig. 21s a plan view of a portion of the same. F 1g. 3 1s a rear elevation of the cutting blades in their normal open condition.

supporting lever 6 fulcrumed on a pin 7 at the rear of the machine and in substantially the plane of the cloth-plate 8 At the front end the press'er-carrying lever 6 is provided with a lateral flange 9 against the upper surface of which a coiled spring 10 socketed in the head of the machine thruststo yieldingly hold the presser-foot downvup'on the feed-dog. The pressure of the foot upon the work may be varied by changing the tenslon of the coiled spring 10 through manipulation of the screw'11 threaded into the head.

I As usual the presser-foot maybe shifted away from thefeed-dog and in the illustrated embodiment. of the invention the resser-foot lifter is inthe form of a nearly horlzontal lever 12 fulcrumedintermediate ,-its ends on a stud-pin 13.tl1readed.into a standard 14 above the cloth-plate of the machine About the pivotpin 13 a-spring 15 is co1led and its ends are. anchored respectively to thepresser-foot'lifting lever and the standard 14. Normally the coiled spring 15 turns the presser-foot lifting lever 12 in a clockwisev direction (as viewed in Fig.1) and holds the too. 16 of the lifting lever spaced slightly from the lateral flange 9 of the presser-carrying lever 6,. The liftingll'ever 12 may be operated manually in any convenient manner preferably through a chain 17 connected to a kneeshift or foottreadle (not shown) below the machine.

The'cutting device comprises a stationary or ledger-blade 18 and a. cutting blade or knife 19 of the shape illustrated inthe drawings. To permit these blades to cut nicely they may be adjusted through the screw-and-slot connections indicated at 20. Either or both of thebladesj18 and 19 may be made of resilient material. In the form of'the invention shown in the drawings the It will be noticed that the ledger-blade 18' has its cutting edge formed laterally oiiits supporting flange and consequently that the passage of work over the rear edge of the cloth-plate is not normally obstructed. lVhile intended especially for cutting chains of stitches, the construction may be used for cutting tape or strips'of material and Y the invention is to be understood as comprehending the same.

The operator may usethe construction of the present invention in various ways. For instance, the successive pieces oi: work may be introduced under the presser-ioot close together or the operator may delay the in troduction of a new piece of work until the machine has chained enough to reach the thread-cutter. In the first case the operator coul'dsever the chains of stitches connecting the successive pieces of work while one piece of work is being operated upon. In the second case the operator would have to delay the introduction of a new piece of work until the preceding piece of work had passed the cutter and thereafter place the .chain between the blades of the cutter for severance. But obviously the. manner in which the attachment maybeused maybe varied by the operator as desired.

' Having thus set forth the nature of the invention, what we'claim herein ispendently of the presser-foot and arranged to cooperate with the ledger-blade Vupon actuation of the presser-foot litter in the direction in which it is moved to lift the presser-foot.

2. In a sewing machine having stitchforming mechanism including a shiftable' element functionating 1n the'normal operation of the'machine and also having a-pivoted lever for moving said element,'a spring normally holding said lever out of engagement with the element an'd'permitting limited movement of the lever without'shifting the element, and shearing mechanism includ ng a blade fixed to said lever and spaced from its pivot, and manualincans for operating said leverandshearing thread without interruption of a stitching opera O -f I i 3. In a sewing machinehaving stitchforming mechanism including" a shiftable element functionating in the normalfoperation ofthe machine and alsohaving a pivoted level for shifting theelementfi said lever being movable independently of the element, and, cutting mechanism including 1. In a sewing machine, a presser-foot, a

severed without interrupting of the machine.

cutting edge spaced from the levers pivot, whereby a. cutting operation'may be performed without shifting the element el. In a sewing machine having a presserfoot, a presser-foot lifter having limited movement independently of the pressersfoot, a ledger-blade mounted on a fixed part of the'machine in rear of the presser-toot, a blade having a cutting edge movable by the presser-foot lifter acrossthe edge of the ledger-blade without shifting the presserfoot. a

5. In a sewing machine having stitchforming mechanism including a shiftable element functionating in the normal operation of the machine and also'having means for moving said element, which means is capable of limited movement independently thereof, a pair of cutting blades one of which is operatively connected to saidmeans and maybe brought into cooperative cutting re lation with the other without interrupting the operationof the sewing machine. I

e. 6. In a thread-cutter forsewing machines,

in combination, a shiftable element, a member for moving said shiftable element having limitedmovement independent ofsaid element, a. cutting blade mounted on said member, a ledger-blade mounted on a sta tionary part of the machine, saidcntting blade beingjmovable across said ledger-blade without displacement of the shiitable element. 7

,7,- A, sewing 'machine having a plurality .of stitch-forming instrumentalities, a member for shifting one of'sai'd stitch-forming instrumentaliti'es, away from-its normal cooperative relation with the other stitchforming instrumentalities and said member 1 having a 'movement independent thereof,

and cutting mechanism including a blade carried by said member whereby st tches connectingsuccessive pieces of work may be 8. In an overedge sewing machine having a cloth-plate, a presser-foot, a spring urging the operation the pressenfoot downnpon the work, means for lifting said resser-foot away from thei work and movable independently or the. presser-foo t, .aqledger-blade. secured to'the cloth-plate atone side of the lineyofseam formationand having a cutting edgeoverhanging the line of seam-formatioma cutting blade secured to said means and adapt ed to, cooperate. with said ledger-blade to sever a chain of stitching, whereby thread may be severed it desired without interrupt:

ing the operation of the machine:

9. In. a sewing machine hav ng a work-c support, in combination, a preSSer-IOQt, a Q

presser-foot lifter normally held "-out of shifting engagement with the presser foot y f y andicapableof limited movementindepend-f ablade secured to said lever and'having a ios I said lifter, and a ledger-blademounted on the work-support, said blades being normally held open and being adapted to sever thread without interrupting the operation of the machine.

10. In an overedge sewing machine having acloth-plate, a presser-foot, means movably supporting the foot, a spring for holding the presser-foot yieldingly down'upon the work, a presser-foot lifting lever ex tending lengthwise in a direction nearly parallel with the cloth-plate and fulcrumed intermediate its ends one of which ends is normally held spaced from engagement with the presser-foot, a cutting blade on the other end of the lifting lever, a ledger-blade on the cloth-plate arranged to cooperate with the first mentioned blade whereby a thread chain may be severed manually without shifting the resser-foot or without interrupting the operation of the machine.

11. In a sewing machine having a work support and a presser-foot, a presser-foot lifter having limited movement independently of the presser-foot, and cuttingmeans located above the work support and connected to said presser-foot lifter, whereby upon actuation of the presser-foot lifter the cutting means may be actuated without shifting the, presser-foot.

12. In a sewing machine, a presser-foot, a prcsser-foot lifter having a limited m0vement independently of said resser-foot, and a thread-cutter connected to be operated by said resser-foot lifter to cut the thread during said limited movement of the resser-foot lifter without necessitating the lifting of the presser-foot.

In testimony whereof, we have signed our names to this specification.

' ENNO H. A. HABBERT.

ELMER STONE. 

